The Federal Energy Regulatory Commission launched a six-month study today to determine how much renewable energy the electric grid can accommodate.

FERC will work with the Lawrence Berkeley National Laboratory on the $500,000 study to validate the preliminary frequency-response tool developed by the commission to gauge the grid's reliability if large quantities of renewable energy are sent to the system.

"We need a good metric – a good yardstick, a tool – to assess how much renewable energy can be injected into the bulk power ... system," said Joseph McClelland, director of FERC's Office of Electric Reliability.

"The bulk power system was constructed over a long period of time with different resources in mind," McClelland continued. "The question is: Considering a renewable portfolio standard or renewable energy requirements that folks are discussing, how much can it take and still remain reliable?"

The frequency response tool could serve as a reliable test of how much renewable energy generation the grid could handle, McClelland said.

All generators on the grid are required to operate at a certain frequency level, McClelland explained. When one generator is lost, others take up the slack, he said, but the system's frequency can drop. The study will coordinate renewable electricity generation with the frequency response mechanism that has been used for years to assess the health of the grid.

"If we put renewable energy on the system in a big way – 10 percent to 25 percent of energy, for instance – what happens if variability materializes those units lost?" McClelland said. "We should see a response in system frequency. And that's probably a good indicator of how much generation the grid can handle."

The study is the first step toward determining how robust the grid currently is and if it can handle variabilities and recover from losses in generation from renewable energy sources, McClelland said. The study will not look at specifics. Instead, it will focus on the overall challenges and shortcomings the grid may have in accepting renewables, he said.

He added the Energy Department would be well-equipped to commission a larger follow-up study.

Since proposed federal renewable-energy requirements could kick in within three years, there is little time to make system changes, McClelland said.

"We need to know how robust the grid is now," he said. "Is the grid able to recover from a loss of generation? And what can be done within a short period of time to shore that up?"

Reprinted from Greenwire with permission from Environment & Energy Publishing, LLC., 202-628-6500